191 research outputs found

    Transannular patching is a valid alternative for tetralogy of Fallot and complete atrioventricular septal defect repair

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    Objective: We report our experience with repair of tetralogy of Fallot associated with complete atrioventricular septal defect, addressing in particular the need for a pulmonary valve in the right ventricular outflow tract. Methods: Between 1992 and 2006, 33 children with tetralogy of Fallot and complete atrioventricular septal defect were admitted; 26 had Down’s syndrome (79%). Thirty-two children had complete repair (18 primary, 14 staged); of the 15 who received initial palliation, 1 died before complete repair. Right ventricular outflow tract obstruction was relieved by transannular patch in 14 cases (42%), infundibular patch with preservation of the pulmonary valve in 7 (21%), and right ventricle–to–pulmonary artery conduit in 11 (33%). Results: There were no hospital deaths. Actuarial survival was 96% 3.9% at 5 years and 85.9 1.1% at 10 years. Multivariate analysis showed that type of relief of right ventricular outflow tract obstruction did not influence survival (P ¼ .16), nor did the choice to use a valved conduit (P ¼ .82). Primary correction (P ¼ .05) and lower weight at repair (P ¼ .05) were associated with higher probability of survival. Mean follow-up was 69.3 5.9 months (range 0.2–282 months). There were 2 late deaths. Overall freedom from reoperation was 69% at 5 years and 38%at 10 years. Right ventricular outflow tract reconstruction without use of a valved conduit allowed a significantly higher freedom from reinterventions (P<.05). Conclusions: Tetralogy of Fallot associated with complete atrioventricular septal defect can be corrected at low risk with favorable intermediate survival. Use of right ventricle–to–pulmonary artery conduit can be avoided in two thirds of patients with no impact on survival, possibly improving overall freedom from reintervention

    The Water Bugs (Heteroptera: Nepomorpha) of the Guyana Region

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    NEPOMORPHA OF THE GUYANA REGION The Nepomorpha of the Guyana Region are keyed out and described. In addition distributional, faunistical and comparative notes on the species are given. New species and subspecies: Ochterus aeneifrons surinamensis, O. tenebrosus; Limnocoris fittkaui surinamensis; Ranatra adelomorpha; Neoplea globoidea; Buenoa amnigenopsis; Tenagobia pseudoromani from Suriname and Ranatra ornitheia from Guyana. New synonyms (junior ones between parenthesis): Gelaslocorus flavus flavus Guér. (G. nebulosus nebulosus Guér.); Pelocoris impicticollis Stål (P. horváthi Mont.), P. poeyi (Guér.) not identical with P. femoratus (P.-B.) (P. convexus Nieser), P. procurrens White (P. minutus Mont.); Belostoma bicavum Lauck ( B. parvoculum Lauck); Ranatra doesburgi De Carlo (R. usingeri De C.), R. macrophthalma H.-S. (R. surinamensis De C.), R. mediana Mont. (R. williamsi Kuitert), R. obscura Mont. (R. annulipes White 1879 not Stål), R. sarmentoi De C. (R. ameghinoi De C.); Buenoa amnigenopsis n. sp. ( B. amnigenus Nieser 1968, 1970 not White), B. amnigenus (White) (B. amnigenoidea Nieser 1970), B. nitida Truxal (B. doesburgi Nieser); Heterocorixa surinamensis Nieser ( H. boliviensis Nieser 1970 not Hungerford); Tenagobia incerta Lundbl. ( T. signata and T. serrata in part, Nieser 1970 not White and Deay respectively), T. socialis (White) (T. serrata in part, Nieser 1970 not Deay)

    Role of Neural NO Synthase (nNOS) Uncoupling in the Dysfunctional Nitrergic Vasorelaxation of Penile Arteries from Insulin-Resistant Obese Zucker Rats

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    Objective: Erectile dysfunction (ED) is considered as an early sign of vascular disease due to its high prevalence in patients with cardiovascular risk factors. Endothelial and neural dysfunction involving nitric oxide (NO) are usually implicated in the pathophysiology of the diabetic ED, but the underlying mechanisms are unclear. The present study assessed the role of oxidative stress in the dysfunctional neural vasodilator responses of penile arteries in the obese Zucker rat (OZR), an experimental model of metabolic syndrome/prediabetes. Methods and Results: Electrical field stimulation (EFS) under non-adrenergic non-cholinergic (NANC) conditions evoked relaxations that were significantly reduced in penile arteries of OZR compared with those of lean Zucker rats (LZR). Blockade of NO synthase (NOS) inhibited neural relaxations in both LZR and OZR, while saturating concentrations of the NOS substrate L-arginine reversed the inhibition and restored relaxations in OZR to levels in arteries from LZR. nNOS expression was unchanged in arteries from OZR compared to LZR and nNOS selective inhibition decreased the EFS relaxations in LZR but not in OZR, while endothelium removal did not alter these responses in either strain. Superoxide anion production and nitro-tyrosine immunostaining were elevated in the erectile tissue from OZR. Treatment with the NADPH oxidase inhibitor apocynin or acute incubation with the NOS cofactor tetrahydrobiopterin (BH4) restored neural relaxations in OZR to levels in control arteries, while inhibition of the enzyme of BH4 synthesis GTP-cyclohydrolase (GCH) reduced neural relaxations i

    Function-Based Discovery of Significant Transcriptional Temporal Patterns in Insulin Stimulated Muscle Cells

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    Background: Insulin action on protein synthesis (translation of transcripts) and post-translational modifications, especially of those involving the reversible modifications such as phosphorylation of various signaling proteins, are extensively studied but insulin effect on transcription of genes, especially of transcriptional temporal patterns remains to be fully defined. Methodology/Principal Findings: To identify significant transcriptional temporal patterns we utilized primary differentiated rat skeletal muscle myotubes which were treated with insulin and samples were collected every 20 min for 8 hours. Pooled samples at every hour were analyzed by gene array approach to measure transcript levels. The patterns of transcript levels were analyzed based on a novel method that integrates selection, clustering, and functional annotation to find the main temporal patterns associated to functional groups of differentially expressed genes. 326 genes were found to be differentially expressed in response to in vitro insulin administration in skeletal muscle myotubes. Approximately 20 % of the genes that were differentially expressed were identified as belonging to the insulin signaling pathway. Characteristic transcriptional temporal patterns include: (a) a slow and gradual decrease in gene expression, (b) a gradual increase in gene expression reaching a peak at about 5 hours and then reaching a plateau or an initial decrease and other different variable pattern of increase in gene expression over time. Conclusion/Significance: The new method allows identifying characteristic dynamic responses to insulin stimulus, commo

    Predicting Spike Occurrence and Neuronal Responsiveness from LFPs in Primary Somatosensory Cortex

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    Local Field Potentials (LFPs) integrate multiple neuronal events like synaptic inputs and intracellular potentials. LFP spatiotemporal features are particularly relevant in view of their applications both in research (e.g. for understanding brain rhythms, inter-areal neural communication and neronal coding) and in the clinics (e.g. for improving invasive Brain-Machine Interface devices). However the relation between LFPs and spikes is complex and not fully understood. As spikes represent the fundamental currency of neuronal communication this gap in knowledge strongly limits our comprehension of neuronal phenomena underlying LFPs. We investigated the LFP-spike relation during tactile stimulation in primary somatosensory (S-I) cortex in the rat. First we quantified how reliably LFPs and spikes code for a stimulus occurrence. Then we used the information obtained from our analyses to design a predictive model for spike occurrence based on LFP inputs. The model was endowed with a flexible meta-structure whose exact form, both in parameters and structure, was estimated by using a multi-objective optimization strategy. Our method provided a set of nonlinear simple equations that maximized the match between models and true neurons in terms of spike timings and Peri Stimulus Time Histograms. We found that both LFPs and spikes can code for stimulus occurrence with millisecond precision, showing, however, high variability. Spike patterns were predicted significantly above chance for 75% of the neurons analysed. Crucially, the level of prediction accuracy depended on the reliability in coding for the stimulus occurrence. The best predictions were obtained when both spikes and LFPs were highly responsive to the stimuli. Spike reliability is known to depend on neuron intrinsic properties (i.e. on channel noise) and on spontaneous local network fluctuations. Our results suggest that the latter, measured through the LFP response variability, play a dominant role

    Heterozygous Mutations of FREM1 Are Associated with an Increased Risk of Isolated Metopic Craniosynostosis in Humans and Mice

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    The premature fusion of the paired frontal bones results in metopic craniosynostosis (MC) and gives rise to the clinical phenotype of trigonocephaly. Deletions of chromosome 9p22.3 are well described as a cause of MC with variably penetrant midface hypoplasia. In order to identify the gene responsible for the trigonocephaly component of the 9p22.3 syndrome, a cohort of 109 patients were assessed by high-resolution arrays and MLPA for copy number variations (CNVs) involving 9p22. Five CNVs involving FREM1, all of which were de novo variants, were identified by array-based analyses. The remaining 104 patients with MC were then subjected to targeted FREM1 gene re-sequencing, which identified 3 further mutant alleles, one of which was de novo. Consistent with a pathogenic role, mouse Frem1 mRNA and protein expression was demonstrated in the metopic suture as well as in the pericranium and dura mater. Micro-computed tomography based analyses of the mouse posterior frontal (PF) suture, the human metopic suture equivalent, revealed advanced fusion in all mice homozygous for either of two different Frem1 mutant alleles, while heterozygotes exhibited variably penetrant PF suture anomalies. Gene dosage-related penetrance of midfacial hypoplasia was also evident in the Frem1 mutants. These data suggest that CNVs and mutations involving FREM1 can be identified in a significant percentage of people with MC with or without midface hypoplasia. Furthermore, we present Frem1 mutant mice as the first bona fide mouse model of human metopic craniosynostosis and a new model for midfacial hypoplasia
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